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A study on the performance characteristics of a testing facility for a water-to-water heat pump
Amoabeng, Kofi Owura,Lee, Kwang Ho,Choi, Jong Min Elsevier 2018 International Journal of Refrigeration Vol.86 No.-
<P><B>Abstract</B></P> <P>Heat pump testing facility is used to investigate the performance and reliability of a heat pump unit. During the testing period, energy is utilized by the facility mainly through cooling with a refrigeration unit and heating with an electric heater to control and maintain the test conditions of the heat pump unit. However, research study on the energy consumption analysis of the heat pump test facility is rarely found in literature. In this study, the performance characteristics of the testing facility for a water-to-water heat pump are investigated according to the variation of heat pump capacity and COP in both cooling and heating operating modes. The objective is to analyze the energy consumption of the test facility used to investigate the performance of a water-to-water heat pump unit. The analysis of experimental test results showed that the total energy consumption rate of the heat pump test facility increased as capacity and COP of heat pump increased in both cooling and heating modes. However, the increment according to COP variation was smaller than capacity variation. Also, the total energy consumption rate of the testing facility was about ten times more than the energy consumption rate of the heat pump unit.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The performance characteristics of a water-to-water heat pump test facility were investigated. </LI> <LI> Experiments were performed with the variation in capacity and COP of heat pump. </LI> <LI> The study was conducted in both heating and cooling operating modes of heat pump unit. </LI> <LI> The energy consumption of the water-to-water heat pump test facility was analyzed. </LI> </UL> </P>
Performance investigation of a novel calorimeter for a heat pump system according to flow loops
Kofi Owura Amoabeng,이광호,JONGMIN CHOI 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.4
Heat pumps cover a wide range of heating and cooling applications owing to their means of drawing out heat from ground, air and water at low temperature. In order to acquire performance data for heat pump certification and rating, the calorimeter is used in measuring the heat pump. In conventional approach of measuring the heat pump with standard test conditions, a great amount of energy is used in the calorimeter for cooling and heating. Using innovative ways to enhance the calorimeter performance is significant for energy and cost savings. Therefore, a novel calorimeter was developed for heat pump measurement. Two different flow loop configurations, specified as cases (1) and (2) were adopted. In the case (1), secondary fluid flow through the heat recovery unit was directly from heat pump test unit heat exchanger while in case (2), secondary fluid flow through heat recovery unit was from constant temperature water bath directly. The energy usage of the novel calorimeter based on the impact of each configuration was analyzed. Experiments were conducted using a water-to-water heat pump unit in heating and cooling approach with variation in operating conditions. Energy analyses based on test data indicated that energy reduction of the novel calorimeter was at least 72 % for heating and 69 % for cooling in relation to energy used in conventional calorimeter. Moreover, for novel calorimeter, case (1) resulted in energy savings of at least 9.1 % for cooling and 13 % for heating in relation to case (2). However, for heat pump units with very low capacities, tests measurements were executed using case (2) configuration because the tests in case (1) resulted in large thermal fluctuations such that the steady operating conditions of the water setpoint temperatures at inlet to the indoor and outdoor heat exchangers of the test unit were unattainable.
Review on Cooling System Energy Consumption in Internet Data Centers
K. O. Amoabeng,J. M. Choi 대한설비공학회 2016 International Journal of Air-Conditioning and Refr Vol.24 No.4
Due to the advancement of the telecommunication and information technology (IT) industry,internet data centers (IDCs) have become widespread in the public and private sectors. As such,energy demand in the center has also become increasingly prominent. Several technologies on energy management have been studied to determine the options available to minimize the energy required to operate the data center as well as reduce greenhouse gas emissions. The cooling system is required to remove the high heat dissipated by the IT electronic components especially the servers in order to ensure safe and reliable working condition. However, it utilizes more than onethird of the total energy consumption in the data center. In this study, the energy efficiency technologies that are usually applied to cooling systems in data centers were reviewed. The aim is to find out the strategies that will reduce the energy consumption of the cooling system since the cooling demand in data center is all year round. Prior to that, the performance metric tool that is mostly used in analyzing data center efficiency was discussed. The conventional cooling system technologies that are utilized in data centers were also provided. Lastly, innovative cooling technologies for future solutions in data centers were discussed.